"This letter serves as an official notice of the unconstitutional activity and demands that the School District terminate this and any similar illegal activity immediately," wrote Monica Miller, Esq. of AHA.

"To avoid legal action, we kindly ask that you notify us in writing within two weeks of receipt of this letter setting forth the steps you will take to rectify this constitutional infringement."

In an interview with The Christian Post, Miller explained that her organization became aware of the convocation courtesy of a teacher who attended the convocation.

"A School District teacher contacted our office regarding the convocation. He wishes to remain anonymous at this time," said Miller. "The School District has yet to formally respond to our letter. We asked that they respond within two weeks so they still have a bit of time."

Miller also told CP that this went beyond merely being offended at religious expression and was "absolutely a constitutional concern."

"The Supreme Court and lower federal courts have made it absolutely clear that prayers are not allowed at public school-sponsored events, and especially not at mandatory events," Miller asserted.

"In Warnock v. Archer … the Eighth Circuit explicitly held that a school's practice of including prayers at mandatory teacher-training meetings was unconstitutional. The court reasoned that the practices were 'constitutionally infirm not because they offended [the teacher] but because they endorsed religion.'"

Some have taken to the defense of Jackson Public School District, including attorney Steve Crampton of the American Center for Constitutional Rights.